Abstract: The unauthorized immigration population on U.S. territory is estimated to stand at 11.5 million. What is to be done about this population? This question might be addressed by the currently uncertain efforts at comprehensive immigration reform. No reform, however, can obviate the need to think about the deportation conundrum – that is, about whether and when deportation is the appropriate response to widespread violations of immigration law. The public debate gravitates towards the misleading opposition of “mass deportation” and “amnesty.” These labels focus unduly on the level of enforcement, or the question of how many people should be deported and how many allowed to remain. This question fails to capture the substantive reasons that lead people to oppose or welcome immigrants in their vicinity and misconceives what is actually at stake in deportation policy. Deportation serves a dual function: it is a screening mechanism and a system of penalties for legal violations. Both of these functions dictate the need to prioritize enforcement on some basis that reflects the perceived costs and benefits that accompany immigrant presence. This Article argues that centrally crafted and nation-wide priorities turn out to be poor proxies for sorting immigrants on the relevant bases. The nature of the consequences of immigrant presence most relevant to priority setting calls for sub-federal participation in this task. Under the status quo, states and localities cannot meaningfully assert their own priorities, but they can overwhelm federal authorities with enforcement requests or obstruct federal enforcement through non-cooperation. In this way, all disagreements between the levels of government culminate in a stand-off regarding levels of enforcement. Opening alternative avenues for sub-federal actors to take part in priority-setting would exploit the sub-federal comparative advantage, and refocus the national debate on the questions about deportation that matter most.